Configurable action buttons with preset templates

Convert the hardcoded Claude / Visual Studio / Redeploy buttons into
a configurable action-button system with an editor UI.

- New config field actions[] with kinds: terminal, detached, open
  (open uses Windows shell association — used by the .sln preset)
- requiresFile supports * globs (e.g. *.sln matches solution files)
- Migration seeds Claude + Visual Studio + Redeploy on first run, with
  a one-time vsActionBackfilled pass to add VS to users who already
  migrated under the previous two-seed flow
- ActionEditor modal: list with reorder/edit/delete, add form with
  preset dropdown (Claude, Visual Studio, VS Code, Cursor, Run
  1ReDeploy.bat, Commit & Push) and a curated icon dropdown plus
  free-text override
- runAction IPC dispatches by kind; isCommandAvailable generalizes
  the per-CLI PATH probe used to disable buttons whose CLI is missing
- Built-in VS button removed from BookmarkRow + MinimizedList; Claude
  visibility toggle removed from settings (now an editable action)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

electron/preload.js

@@ -27,7 +27,7 @@ contextBridge.exposeInMainWorld('bookmarks', {
 
   // Folder picking + inspection
   pickFolder: () => ipcRenderer.invoke('pick-folder'),
-  inspectFolder: (path) => ipcRenderer.invoke('inspect-folder', path),
+  inspectFolder: (path, actionFiles) => ipcRenderer.invoke('inspect-folder', path, actionFiles),
 
   // Launchers
   openInExplorer: (path) => ipcRenderer.invoke('open-in-explorer', path),
@@ -37,6 +37,8 @@ contextBridge.exposeInMainWorld('bookmarks', {
   runRedeploy: (path) => ipcRenderer.invoke('run-redeploy', path),
   copyPath: (text) => ipcRenderer.invoke('copy-path', text),
   isClaudeAvailable: () => ipcRenderer.invoke('is-claude-available'),
+  isCommandAvailable: (name) => ipcRenderer.invoke('is-command-available', name),
+  runAction: (payload) => ipcRenderer.invoke('run-action', payload),
 
   // Window
   setPinned: (value) => ipcRenderer.invoke('set-pinned', value),
@@ -47,6 +49,7 @@ contextBridge.exposeInMainWorld('bookmarks', {
   // Settings
   setButtonVisibility: (payload) => ipcRenderer.invoke('set-button-visibility', payload),
   setAutoStart: (value) => ipcRenderer.invoke('set-auto-start', value),
+  setActions: (list) => ipcRenderer.invoke('set-actions', list),
 
   // Events from main → renderer
   onConfigUpdated: (cb) => {